17.04.10
A.B

Big Idea
Negative numbers help us to model many real world situations.

Essential Question: How can I add integers?
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Notes from class:
  • An absolute value is the number’s distance from the zero
  • If the absolute value of a number is bigger than the answer will always get that number’s symbol.

Problem 2.2: Inventing A New Model

A. Use a chip board and black and red chips to find each sum. Draw each series of chip boards to illustrate your work.
  1. -8+-7=-1
  2. -8+7=-15
  3. 8+-7=1
  4. 8+7=15
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B. Find two combinations of black and red chips that will simplify to represent the given integer. Draw a series of chip boards to prove that each combination works.
  1. -3
  2. +5
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C. Write each combination you found in part B as an addition sentence.
  1. -2+-1=-3
  2. 3+2=5


Problem 2.2 follow-up:

1. What integer added to -8 gives a sum of -4?
-8+4=-4

2. Give two integers with a sum that is less than either of the two integers.
-2+-4=-6

3. Give two integers with a sum that is greater than wither of the two integers.
5+7=12

4. Use Conrado’s method to compute the following sums in your head.
a. 9+-7=2
b. -80+50=30
c. 35+-27=8
d. -8+-5=-13